William Osler, another great physician, placed his typhoid fever patients in a cold bath in the 1890s.

Fast-forward to the 1930s, and neurosurgeons hypothesized that ice water baths might stop cancer cells from multiplying.

During the 1950s, efforts had shifted to using hypothermia in the operating room during cardiac surgery. Researchers began to report that animals that were cooled had good recovery after their hearts stopped and were restarted. The premise was then applied to human subjects. A brief article from the Journal of the American Medical Association in 1960 describes a 2-year old girl who recovered from a cardiac arrest after her body temperature was brought down with a “watercooled mattress.”

Hypothermia equipment, used at the University of Colorado Medical Center in 1953, is in the Smithsonian Institution in Washington, D.C., as a medical “landmark.”

By 1964, Peter Safar – the University of Pittsburgh physician who is credited with pioneering cardiopulmonary resuscitation – actually included hypothermia in his recommendations for what doctors should do after successfully restarting a patient’s heart.

This apparatus for use during open heart surgery was developed by Charles Drew at Westminster Hospital in the UK. It cooled patients by passing blood through a heat exchanger.

During this time, the theory was that cooling limited the brain’s use of oxygen and slowed metabolism, thus mitigating damage. To that end, patients were cooled to body temperatures as low as 85 degrees, and hypothermia was often prolonged for days. This led to complications that were difficult to manage: irregular heart rhythms, infection, bleeding. Excitement among much of the medical field diminished.

Back at Safar’s lab at the University of Pittsburgh, research efforts began anew in the 1980s. There, researchers experimented with milder degrees of hypothermia, and found that even with less risky temperatures, their animal subjects could make a good recovery after cardiac arrest. This laid important groundwork.

But it wasn’t until 2002 that interest in hypothermia treatment was renewed with the publishing of a pair of papers in the New England Journal of Medicine. Two different teams of researchers, one in Australia and another in Europe, studied the effects of cooling on patients who had survived a cardiac arrest. Both groups found that lowering the body temperature to around 91 degrees Fahrenheit for 12 to 24 hours significantly improved brain function.